Limits...
Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

Egger F, Meyer T, Such U, Hecksteden A - PLoS ONE (2014)

Bottom Line: The main outcome measure was the time to exhaustion in the constant load test.Cycling time to exhaustion was improved (p<0.05) under BICA (49.5±11.5 min) compared with placebo (45.0±9.5 min).The results suggest that ingestion of BICA may improve prolonged, high-intensity cycling performance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany.

ABSTRACT

Background: While the ergogenic effect of sodium bicarbonate (BICA) on short-term, sprint-type performance has been repeatedly demonstrated, little is known about its effectiveness during prolonged high-intensity exercise in well-trained athletes. Therefore, this study aims to examine the influence of BICA on performance during exhaustive, high-intensity endurance cycling.

Methods: This was a single-center, double-blind, randomized, placebo-controlled cross-over study. Twenty-one well-trained cyclists (mean ± SD: age 24±8 y, BMI 21.3±1.7, VO2peak 67.3±9.8 ml·kg-1·min-1) were randomly allocated to sequences of following interventions: oral ingestion of 0.3 g·kg-1 BICA or 4 g of sodium chloride (placebo), respectively. One h after ingestion subjects exercised for 30 min at 95% of the individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion. Prior to these constant load tests stepwise incremental exercise tests were conducted under both conditions to determine IAT and VO2peak. Analysis of blood gas parameters, blood lactate (BLa) and gas exchange measurements were conducted before, during and after the tests. The main outcome measure was the time to exhaustion in the constant load test.

Results: Cycling time to exhaustion was improved (p<0.05) under BICA (49.5±11.5 min) compared with placebo (45.0±9.5 min). No differences in maximal or sub-maximal measures of performance were observed during stepwise incremental tests. BICA ingestion resulted in an increased pH, bicarbonate concentration and BLa before, throughout and after both exercise testing modes.

Conclusion: The results suggest that ingestion of BICA may improve prolonged, high-intensity cycling performance.

Trial registration: German Clinical Trials Register (DRKS) DRKS00006198.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the general design.Both stepwise incremental tests and constant load tests were conducted under two conditions: either after oral ingestion of 0.3 g·kg−1 sodium bicarbonate (BICA) or 4 g of sodium chloride (placebo). Time interval between tests is specified in days (d). Data are presented as means ± standard deviation respectively, with minimum (min) and maximum (max) values.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4262454&req=5

pone-0114729-g001: Schematic representation of the general design.Both stepwise incremental tests and constant load tests were conducted under two conditions: either after oral ingestion of 0.3 g·kg−1 sodium bicarbonate (BICA) or 4 g of sodium chloride (placebo). Time interval between tests is specified in days (d). Data are presented as means ± standard deviation respectively, with minimum (min) and maximum (max) values.

Mentions: In a double-blind, randomized cross-over design, subjects underwent two stepwise incremental exercise tests and two constant load tests (with two phases) on an electrically braked cycle ergometer (Excalibur Sport, Lode, Groningen, The Netherlands). An overview of the design is given in Fig. 1. Each test type was completed under the following conditions: either after oral ingestion of 0.3 g·kg−1 BICA, or 4 g sodium chloride (placebo). Both supplements were solved in 0.7 l water. Randomization was performed as simple random allocation; each subject identifier was forwarded to a person who had no further relationship to the conduct of the study, and who performed the randomization blindly using a random draw of numbers. This person also prepared the BICA or placebo drinks, respectively and deposited them in a blank sports bottle in the ergometry lab before entry of subject or testing staff.


Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

Egger F, Meyer T, Such U, Hecksteden A - PLoS ONE (2014)

Schematic representation of the general design.Both stepwise incremental tests and constant load tests were conducted under two conditions: either after oral ingestion of 0.3 g·kg−1 sodium bicarbonate (BICA) or 4 g of sodium chloride (placebo). Time interval between tests is specified in days (d). Data are presented as means ± standard deviation respectively, with minimum (min) and maximum (max) values.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4262454&req=5

pone-0114729-g001: Schematic representation of the general design.Both stepwise incremental tests and constant load tests were conducted under two conditions: either after oral ingestion of 0.3 g·kg−1 sodium bicarbonate (BICA) or 4 g of sodium chloride (placebo). Time interval between tests is specified in days (d). Data are presented as means ± standard deviation respectively, with minimum (min) and maximum (max) values.
Mentions: In a double-blind, randomized cross-over design, subjects underwent two stepwise incremental exercise tests and two constant load tests (with two phases) on an electrically braked cycle ergometer (Excalibur Sport, Lode, Groningen, The Netherlands). An overview of the design is given in Fig. 1. Each test type was completed under the following conditions: either after oral ingestion of 0.3 g·kg−1 BICA, or 4 g sodium chloride (placebo). Both supplements were solved in 0.7 l water. Randomization was performed as simple random allocation; each subject identifier was forwarded to a person who had no further relationship to the conduct of the study, and who performed the randomization blindly using a random draw of numbers. This person also prepared the BICA or placebo drinks, respectively and deposited them in a blank sports bottle in the ergometry lab before entry of subject or testing staff.

Bottom Line: The main outcome measure was the time to exhaustion in the constant load test.Cycling time to exhaustion was improved (p<0.05) under BICA (49.5±11.5 min) compared with placebo (45.0±9.5 min).The results suggest that ingestion of BICA may improve prolonged, high-intensity cycling performance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany.

ABSTRACT

Background: While the ergogenic effect of sodium bicarbonate (BICA) on short-term, sprint-type performance has been repeatedly demonstrated, little is known about its effectiveness during prolonged high-intensity exercise in well-trained athletes. Therefore, this study aims to examine the influence of BICA on performance during exhaustive, high-intensity endurance cycling.

Methods: This was a single-center, double-blind, randomized, placebo-controlled cross-over study. Twenty-one well-trained cyclists (mean ± SD: age 24±8 y, BMI 21.3±1.7, VO2peak 67.3±9.8 ml·kg-1·min-1) were randomly allocated to sequences of following interventions: oral ingestion of 0.3 g·kg-1 BICA or 4 g of sodium chloride (placebo), respectively. One h after ingestion subjects exercised for 30 min at 95% of the individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion. Prior to these constant load tests stepwise incremental exercise tests were conducted under both conditions to determine IAT and VO2peak. Analysis of blood gas parameters, blood lactate (BLa) and gas exchange measurements were conducted before, during and after the tests. The main outcome measure was the time to exhaustion in the constant load test.

Results: Cycling time to exhaustion was improved (p<0.05) under BICA (49.5±11.5 min) compared with placebo (45.0±9.5 min). No differences in maximal or sub-maximal measures of performance were observed during stepwise incremental tests. BICA ingestion resulted in an increased pH, bicarbonate concentration and BLa before, throughout and after both exercise testing modes.

Conclusion: The results suggest that ingestion of BICA may improve prolonged, high-intensity cycling performance.

Trial registration: German Clinical Trials Register (DRKS) DRKS00006198.

No MeSH data available.


Related in: MedlinePlus